Overview Screen

The screen refresh rate, in seconds.

The number of DBEnvironment sessions.

A scale showing the number of transactions that can be active at one time. The maximum appears at the far right of the scale, and the first three numbers on the scale are 1/4, 1/2, and 3/4 of the maximum.

The number of transactions that have started but have not terminated (that is, a BEGIN WORK statement has completed but a COMMIT WORK statement has not yet begun.)

The number of active transactions that are blocked because they are waiting for a lock owned by another session. To determine the amount of lock contention, compare the IMPEDE XACT value with the ACTIVE XACT and SESSIONS values.

The percentage of pages that are not in the data buffer pool at request time. The operating system must fetch these pages, either from the operating system buffer pool or by a physical disk read.

The percentage of lock requests postponed because another session held an incompatible lock.

The percentage of runtime control block space that is occupied, calculated as follows:

  RUNTIME CB % = (Used Pages / Max Pages) * 100

Each runtime control block page holds 4096 bytes. Lock management is the single greatest user of runtime control block space.

The number of runtime control block pages in use.

The maximum number of runtime control block pages. The ControlBlockPages parameter that you specify in the START DBE, START DBE NEW, or START DBE NEWLOG statements is used to calculate MAX PAGES. MAX PAGES is usually smaller than ControlBlockPages, and if ControlBlockPages is too small, MAX PAGES is set to a certain minimum value.

The percentage of log file space that is occupied, as calculated by the following formula:

  LOG FULL % = (Used LgPgs / Max LgPgs ) * 100

A log page contains 512 bytes.

The number of log pages that have been written.

The maximum number of log pages. To change this value, issue either the SQL START DBE or the SQLUtil ALTDBE command.

Either ON or OFF, to indicate archive or nonarchive logging.

The entire LOG ERRORS bar is displayed in inverse video whenever an internal log counter is set to a nonzero value. Two internal log counters are used, one for each log file. With single logging, the log file is corrupt if a log error occurs. With dual logging, the logs are corrupt only if errors occur when writing to both log files. To prevent data loss, you should immediately store the DBEnvironment whenever a log error is encountered.